1. Field of the Invention
This invention relates to entertainment systems and more specifically to display systems integrated into entertainment systems utilized on transportation vehicles.
2. Description of the Related Art
Today's world involves numerous situations in which one is required to endure trips of varying distance and time for both pleasure and work reasons. To accomplish these travels a wide assortment of personal and commercial vehicles including automobiles, buses, ships, trains and aircraft are relied upon on a daily basis. For those individuals not operating the respective vehicle, the duration of the trip provides a captive situation which is often addressed by access to wireless broadcast information, such as television, or viewing pre-recorded information stored on the vehicle for playback during the trip. Such systems are often referred to as on-board entertainment system or mobile entertainment systems. With advances in electronics in recent years, with respect to size, cost and ruggedness, such on-board entertainment systems are commonly found in numerous vehicles.
There are numerous patents that have issued that have involved advances in display systems for on-board entertainment systems. These include, for example, the following patents:
U.S. Pat. No. 5,467,106 entitled “Retractable Face-Up LCD Monitor with Off-Monitor Power Supply and Back-EMF Braking”, issued to A. H. Salomon, discloses a retractable LCD monitor for use in aircraft and the like that is supplied with power from a power supply that is secured in a fixed off-monitor location on the monitor's housing. The power supply also provides power for a motor assembly that controls a pivoting of the monitor between open and retracted positions. This configuration allows for a compact monitor assembly that can be stowed screen up within a restricted space housing, thus protecting the display from damage by passengers and presenting a pleasing appearance, while still pivoting the monitor by more than 90° to its open position. The motor that is used to pivot the monitor to the open position remains coupled to the monitor pivot mechanism during the retraction cycle, providing a back-emf that resists a spring force used to retract the monitor, and thereby cushion its retraction.
U.S. Pat. No. 6,445,573 entitled “Spring Cam Mechanism for Stowing a Monitor”, issued to J. Portman, et al., discloses an apparatus which includes a frame, a video monitor display mounted to the frame, a torque shaft coupled to the frame such that rotation of the torque shaft causes the frame to pivot along a predetermined arc. The apparatus further involves engaging to the torque shaft to impart rotational motion to the torque shaft, a releasable cam follower slidably disposed on the cam shaft and a spring mounted on the cam shaft exerting a spring bias force directed toward the cam so as to cause rotational motion of the cam.
U.S. Pat. No. 5,811,791 entitled “Method and Apparatus for Providing a Vehicle Entertainment Control System Having an Override Control Switch”, issued to J. Portman, discloses a method and apparatus for providing a vehicle entertainment control system that controls a plurality of display units. The vehicle entertainment control system includes a remote override control circuit capable of activating a remote signal for moving at least one of the plurality of display units between a first position and a second position. In addition, the vehicle entertainment control system includes a local display unit movement control circuit coupled to one of the plurality of display units. The local display unit movement control circuit includes a photodiode coupled to said local display unit movement control circuit, the photodiode transmits a light beam capable of being reflected from a reflective surface near the photodiode to make a reflected light beam, and a photodetector coupled to the local display unit movement control circuit, the photodetector providing a signal to the local display unit control circuit upon detection of said reflected light beam to move one of the display units between the first position and the second position.
U.S. Pat. No. 7,148,935 entitled “On-Board Entertainment System Entertainment Display Retractor Position Sensor”, issued to C. Ho, et al., discloses a position sensor for determining the relative physical location of a movable item via a combination of a sensor and an indicator plate affixed to an actuator device.
U.S. Pat. No. 6,424,386 entitled “Liquid Crystal Display Device”, issued to T. Shimizu, discloses a liquid crystal display device comprising a housing mounted to a ceiling member of an airplane. An image control unit is fixed to the housing, and a liquid crystal display is fixed to a main shaft positioned at a center of rotation. In a retracting unit, a liquid crystal panel of the liquid crystal display is opposed to the image control unit, and stored inside a cover surrounding the housing. The whole height of the liquid crystal display device may be reduced, so as to secure the overhead clearance of the passengers.
In vehicles and particularly in aircraft minimizing size, weight, and power consumption of all systems on board is a significant discriminator when selecting equipment. On large aircraft, the on-board display systems are the largest power consuming systems and this translates into additional fuel to drive electrical power generation. On very small aircraft, there is likely to be no display system, due to the overall availability of power. The weight of equipment is a discriminator because additional ounces of equipment reduce the range between refueling and translates to additional fuel expenditures. Due to the limited space on vehicles, minimizing the equipment size allows for more passenger space in the cabin.
The technology of a Pico projector (also known as a handheld projector, pocket projector or mobile projector) is an emerging technology that applies the use of a handheld device. It is a response to the emergence of compact portable devices such as mobile phones, personal digital assistants, and digital cameras which have sufficient storage capacity to handle presentation materials but little space to accommodate an attached display screen. Handheld projectors involve miniaturized hardware and software that can project digital images onto any nearby viewing surface, such as a wall. The system comprises four main parts: the electronics, the light sources (e.g. LED or laser), the combiner optic, and the scanning mirrors. First, the electronics system turns the image into an electronic signal. Next the electronic signals drive light sources with different colors and intensities down different paths. In the combiner optic the different light paths are combined into one path demonstrating a palette of colors. Finally, the mirrors copy the image pixel by pixel and can then project the image. This entire system is compacted into one very tiny chip. An important design characteristic of a handheld projector is the ability to project a clear image, regardless of the physical characteristics of the viewing surface. (http://en.wikipedia.org/wiki/Handheld_projector[5/17/2010])
In front projector systems “keystoning” is problematic. “Keystoning” occurs when a projector is aligned non-perpendicularly to a screen, or when the projection screen has an angled surface. The image that results from one of these misalignments will look trapezoidal rather than square. There are basically two methods of keystone correction, manual and digital. Manual keystone correction is essentially a physical adjustment to the lens of the projector so that it projects at an angle higher or lower than it would be if it were on a flat surface. Digital correction involves altering the image before it reaches the projection lens. (http://www.projectorpeople.com/resources/keystone-correction.asp [6/6/2010])
Although pico projectors have been utilized in a variety of applications those applications have not included aircraft on-board entertainment systems.